Primary yolk sac tumour of the prostate mimicking small round blue cell tumour.

Prostatic yolk sac tumour is a germ cell tumour with a wide range of age of occurrence, unusual anatomic locations, diverse morphologic patterns, and aggressive biologic behavior, posing challenges both to diagnosis and clinical management. We report a rare case of primary yolk sac tumour of the prostate with extensive local and liver metastasis, the latter of which exhibited sheets of small blue cells expressing CD99 and focal sall4 on biopsy. Positivity for CD99 and gata3 in the initial biopsy raised the differential diagnosis of Ewing sarcoma and poorly differentiated carcinoma. The primary tumour demonstrated an admixture of solid and glandular growth patterns and occasional Schiller-Duval bodies. A panel of immunohistochemical stains showing positivity for AE1/3, sall4, cdx2, and focal alpha-fetoprotein, and negativity for oct-4, facilitated the diagnosis. A thorough review of the literature and our current report indicate that a large tumour load, incomplete tumour resection, limited response to preoperative neoadjuvant chemotherapy, and late stage of the disease are predictive factors for a poor clinical outcome.

[Hereditary neuropathy with liability to pressure palsies in childhood: Report of three cases]. / Neuropathie héréditaire par hypersensibilité à la pression : à propos de 3 observations chez l'enfant.

Hereditary neuropathy with liability to pressure palsy (HNPP) is an autosomal dominant neuropathy. It is characterized by recurrent sensory and motor nerve palsies, usually precipitated by minor trauma or compression. Even though rare in childhood, this disorder is probably underdiagnosed given its wide spectrum of clinical symptoms. We review three separate cases of HNPP diagnosed in children with various phenotypes: fluctuating and distal paresthesias disrupting learning at school, cramps related to intensive piano practice, and discrete muscle weakness with no functional complaint. Family history should be carefully reviewed to identify potential undiagnosed HNPP cases, as in our three reports. Electrophysiological study is essential for the diagnosis, with a double advantage: to confirm the presence of focal abnormalities in clinically symptomatic areas and to guide molecular biology by revealing an underlying demyelinating polyneuropathy. The diagnosis of HNPP is confirmed by genetic testing, which in 90% of cases shows a 1.5-Mb deletion of chromosome 17p11.2 including the PMP22 gene. Patients are expected to make a full recovery after each relapse. However, it is very important for both the patient and his or her family to establish a diagnosis in order to prevent recurrent palsy brought on by situations involving prolonged immobilizations leading to nerve compression.

[Knowledge and experience of 2- to 15-year-old children's parents consulting in pediatric emergency departments for asthma]. / Évaluation des connaissances et du vécu des parents d'enfants asthmatiques âgés de 2 à 15ans consultant en service d'accueil des urgences pédiatriques.

INTRODUCTION: This study aimed at assessing parents' knowledge and perception in relation to their child's condition when arriving at the emergency ward following an asthma attack. The overall objective was to determine how parent education could be improved. MATERIALS AND METHODS: This study was conducted over 9 months as a multicenter descriptive and qualitative study based on a self-administered questionnaire for parents of asthmatic children, aged 2-15 years. RESULTS: The questionnaire was delivered to 88 children out of 1472 (6%). Approximately 69% of the children included in the study presented with partially controlled or uncontrolled asthma. Fifty percent of the patients were insufficiently monitored and without therapy. Half of the parents said they had never received any information concerning their child's condition. The majority (86%) did not know the basic cause of the disease, 30% percent were unable to detect the features of clinical exacerbation, and 17% were not using an adequate emergency protocol. The illness experience was relatively easy for two-thirds of the children and the parents' perceptions were in line in 50% of the cases. DISCUSSION: Knowledge of parents and their children suffering from asthma is insufficient for optimal control and disease management. Instructions on detecting the signs of asthma severity as well as the establishment of an individualized emergency protocol and medical follow-up should be of prime concern and could reduce emergency department use. CONCLUSION: Doctors have a key role to play in educating and explaining disease characteristics to patients and their families. Therapeutic education also needs to be intensified.

Co-activation of VTA DA and GABA neurons mediates nicotine reinforcement.

Smoking is the most important preventable cause of mortality and morbidity worldwide. This nicotine addiction is mediated through the nicotinic acetylcholine receptor (nAChR), expressed on most neurons, and also many other organs in the body. Even within the ventral tegmental area (VTA), the key brain area responsible for the reinforcing properties of all drugs of abuse, nicotine acts on several different cell types and afferents. Identifying the precise action of nicotine on this microcircuit, in vivo, is important to understand reinforcement, and finally to develop efficient smoking cessation treatments. We used a novel lentiviral system to re-express exclusively high-affinity nAChRs on either dopaminergic (DAergic) or γ-aminobutyric acid-releasing (GABAergic) neurons, or both, in the VTA. Using in vivo electrophysiology, we show that, contrary to widely accepted models, the activation of GABA neurons in the VTA plays a crucial role in the control of nicotine-elicited DAergic activity. Our results demonstrate that both positive and negative motivational values are transmitted through the dopamine (DA) neuron, but that the concerted activity of DA and GABA systems is necessary for the reinforcing actions of nicotine through burst firing of DA neurons. This work identifies the GABAergic interneuron as a potential target for smoking cessation drug development.

Treatment of acute decompensation of maple syrup urine disease in adult patients with a new parenteral amino-acid mixture.

BACKGROUND: Acute decompensation of maple syrup urine disease (MSUD) is usually treated by enteral feeding with an amino-acid mixture without leucine (Leu), valine or isoleucine. However, its administration is ineffective in cases of gastric intolerance and some adult patients refuse enteral feeding via a nasogastric tube. We developed a new parenteral amino-acid mixture for patients with MSUD. METHODS: Seventeen decompensation episodes in four adult patients with MSUD treated with a parenteral amino-acid mixture (group P) were compared to 18 previous episodes in the same patients treated by enteral feeding (group E). RESULTS: The mean Leu concentration at presentation was similar in the groups P and E (1196.9 µmol/L and 1212.2 µmol/L, respectively). The mean decrease in the Leu concentration during the first 3 days of hospitalisation was significantly higher in group P than group E (p = 0.0026); there were no side effects. The mean duration of hospitalisation was similar (4 vs. 4.5 days, p = NS). No patient in group P deteriorated whereas one patient in group E required dialysis. CONCLUSION: This new parenteral amino-acid mixture is safe and allows efficient Leu concentration decrease during acute MSUD decompensation episodes in adults. Its use avoids the need for nasogastric tube insertion.

[Polymorphic expression of epilepsy and cognitive impairment in ring chromosome 20 syndrome]. / Polymorphisme d'expression de l'atteinte épileptique et cognitive du syndrome du chromosome 20 en anneau.

Ring chromosome 20 syndrome combines epilepsy with varying levels of mental retardation, behavioral disorders, and malformations. Epilepsy is generally serious, with frequent drug resistance. The pathophysiology of seizures remains unclear. Rearrangements of two epilepsy genes, CHRNA4 and KCNQ2, have been raised as the cause. We report the observation of one child, with a telomeric deletion 20p13, with no epileptic symptoms. Preservation of CHRNA4 and KCNQ2 gene activity could explain this distinctive feature.

[Theriaque: independent-drug database for good use of drugs by health practitioners]. / Thériaque : base de données indépendante sur le médicament, outil de bon usage pour les professionnels de santé.

Thériaque is a French-drug database, which was created 25 years ago by the centre national hospitalier d'information sur le médicament (CNHIM). The aim was to collect and diffuse independent information to healthcare professionals. From the beginning, the database had two objectives: information access and data input into prescription/dispensary software. Initially accessible via Minitel, then on CD-ROM, Thériaque has been integrated into hospital software. Since 1998, Thériaque is available on the Internet (www.theriaque.org). Today, the CNHIM develops Thériaque in a totally independent way. The eight main qualities of Thériaque are: firstly, independence from pharmaceutical companies and the national healthcare insurance fund; secondly, exhaustive data collection: Thériaque gathers official information and information from reference books; thirdly, reliability: validation of the work carried out by pharmacists, references of all information sources; fourthly, accessibility: free Internet site for all health professionals, prescription analyses; fifthly, originality: integration of an international thesaurus with input from WHO or the European Pharmacopeia and scientific validated information; sixthly, interactivity with users: letterbox, user groups, identification of the needs of health professionals; seventhly, collaboration with other databases or health authorities, that is, EMEA, INCa, HAS or AFSSAPS, which made it possible to develop the concept of infovigilance; eighthly, interoperability: undoubted identification of a drug allowing secure communication between different software. The number of users increased regularly: 41,000 monthly users of the Internet site at the end of 2006 and 216 hospitals using software-integrating Thériaque. Thériaque participates in ensuring the safety of the drug circuit and helps prevent iatrogenic events as it has been defined in France in the decree of 24th August 2005.

[Kinetics of Pseudomonas aeruginosa virulence gene expression during chronic lung infection in the murine model]. / Cinétique d'expression des gènes de virulence de Pseudomonas aeruginosa au cours d'une infection pulmonaire chronique dans le modèle murin.

UNLABELLED: Pseudomonas aeruginosa is a Gram-negative bacillus frequently encountered in human diseases. P. aeruginosa produces a large number of secreted and cell associated virulence factors. Their production is coordinated by various systems of gene regulation. The correlation and sequential intervention of regulation systems during a pulmonary infection have not been determined yet. OBJECTIVE: The aim of this study was to analyze the expression of three P. aeruginosa virulence genes (exoS, lasI, and algD) during the first seven days of chronic lung infection. To do so, mice were infected intratracheally with agarose beads containing P. aeruginosa. RESULTS: The results were a progressive decrease of exoS transcription and an increase of algD, and lasI transcription during infection. This dynamic evolution was consistent with the clinical observation, which demonstrated a progressive loss of type III secretion system function and an increase in the mucoid phenotype development in P. aeruginosa strains from cystic fibrosis patients. CONCLUSION: The development of a P. aeruginosa pulmonary chronic infection associates a decrease of gene expression related to a type III secretion system and an increase of alginate production.

[Early neonatal bacterial infections: could superficial bacteriologic samples at birth be limited?]. / Infections bactériennes néonatales précoces en maternité: peut-on limiter les prélèvements bactériologiques périphériques en salle de naissance ?

INTRODUCTION: Without promptly started antibiotic therapy, early neonatal bacterial infections incur a significant mortality. Superficial bacteriologic samples at birth have in France a real place for the diagnosis and the decision to treat a neonate. OBJECTIVES: In order to limit their indication and their choice, the aim of this article was to describe the proportion of neonates with samples and to determine the diagnostic value of the gastric aspirate, the ear swab and the placental sample. METHODS: Neonates born in the CHRU of Lille in 2005 and staying in the maternity ward were prospectively included. Criteria for samples, type of samples and diagnosis taken were noted. Sensibility, specificity, positive and negative predictive values and likelihood ratios for a positive test and a negative test were calculated. RESULTS AND CONCLUSION: This study included 3918 neonates; 1.7% (65 children) were infected according to our criteria; 42.3% received bacteriologic samples. In accordance with the Anaes guidelines (2002), if mothers were Group B Streptococci positive and received intrapartum antibiotics (up to 2 injections) or did not have any screening test without any other indication of samples, the neonate did not have to receive bacteriologic samples. The gastric aspirate was the best exam thanks to the excellent negative predictive value of its direct examination: 99.4% (IC 95%: 98.8-99.7), its high likelihood ratio for a positive test: 10.04 (IC 95%: 8.29-12.15) and its low likelihood ratio for a negative test: 0.16 (IC 95%: 0.09-0.29); this sample could restrict the antibiotics' ratio given to the neonate. Placental sample could be taken only in certain indications.

Decline in pneumococcal meningitis after the introduction of the heptavalent-pneumococcal conjugate vaccine in northern France.

BACKGROUND: The impact of the heptavalent-pneumococcal conjugate vaccine on the incidence of pneumococcal meningitis in Europe has not yet been assessed. OBJECTIVE: To determine whether heptavalent-pneumococcal conjugate vaccine implementation in northern France has resulted in a decrease in the incidence of pneumococcal meningitis in children. DESIGN: Multicentre retrospective cohort study from 2000 through 2005. SETTINGS: All paediatric departments of the 18 hospitals in northern France. PATIENTS: Patients <18 years of age, admitted for laboratory-confirmed pneumococcal meningitis during the study period, were included. INTERVENTIONS: Data were collected from medical files and the microbiological laboratories of each hospital and compared with the regional hospital discharge codes, using a capture-recapture method. MAIN OUTCOME MEASURES: The study assessed and compared global and age-related incidence rates of pneumococcal meningitis in 2001 (pre-vaccine era) and 2005. RESULTS: 77 cases were found through the capture-recapture method. The incidence rate of pneumococcal meningitis varied from 1.65/100,000 children <18 years in 2001 to 0.80/100,000 children in 2005 (53% reduction, 95% CI 31 to 74; p = 0.08). This has so far been significant only for children <2 years of age (8.9/100,000 in 2001 to 1.8/100,000 in 2005; 82% reduction, 95% CI 52 to 95; p = 0.03). CONCLUSION: A decline in pneumococcal meningitis has been observed in infants since heptavalent-pneumococcal conjugate vaccination began in our area.

[Self-collected vaginal swabs to diagnosis bacterial vaginosis during pregnancy: A pilot study]. / Autoprélèvement vaginal à la recherche d'une vaginose bactérienne pendant la grossesse: étude pilote.

OBJECTIVE: To study the feasibility of a screening for bacterial vaginosis by a self-collected vaginal swab during pregnancy. To measure bacterial vaginosis prevalence in a non-representative sample of women. PATIENTS AND METHODS: A self-collected swab was suggested to 398 women who consulted between 15 and 33 weeks of gestation in three different centres. Gram stain evaluation using Nugent criteria was used for the diagnosis of bacterial vaginosis. RESULTS: Three hundred and forty-one women agreed to take part in the study (86%). The quality of the swabs was satisfactory in 93% of the cases. Concerning the 15 non-interpretable slides, the cellular and bacterial density was too poor, owing to a poor quality or a low vaginal flora. Thirty-one women (9%) had a bacterial vaginosis--Nugent score included between 7 and 10--and this frequency did not vary according to the centre. Thirty-five women (10%) had an intermediate flora--score between 4 and 6--and this result varied from 2 to 12% depending on the centre, but the difference was not significant. DISCUSSION AND CONCLUSION: Self-collected swabs to detect bacterial vaginosis are well accepted by most of pregnant women, and the quality of the swabs seems to be satisfactory. In case vaginal flora is intermediate--between 4 and 6--the interpretation of the slides could be difficult.

[Vaccinal status in children with seizures: a retrospective study conducted in the Bordeaux child hospital]. / Statut vaccinal d'enfants ayant un antécédent de convulsion ou d'épilepsie débutante: étude rétrospective comparative réalisée au CHU de Bordeaux.

UNLABELLED: Vaccination is a common act in medicine. Some serious side effects are always feared in a preventive action, mainly among high-risk patients such as epileptic children or children having already experienced a seizure. OBJECTIVES: To study consequences of such background on the vaccine medical practice. POPULATION AND METHODS: A retrospective study comparing the vaccine statute of children with or without case history of seizures was carried out by the neurologic and paediatric emergencies departments. The study compared 55 with seizures versus 109 without. RESULTS: On the whole, the 2 groups were insufficiently vaccinated. A statistically significant difference was highlighted between the 2 groups for the vaccination coverage by vaccine DTP (diphtheria-tetanus-pertussis) (P=0.017) and MMR (measles-mumps-rubella) (P=0.004). However, concerning the vaccination against hepatitis B, no difference was found. CONCLUSION: The usual contra-indications of these vaccines do not explain this difference and progress must be made to improve the vaccination coverage of epileptic children.

[Evaluation of a new E-test method for antimicrobial sensitivity testing of Pseudomonas aeruginosa isolates from cystic fibrosis]. / Etude multicentrique portant sur l'évaluation d'une méthode simplifiée d'analyse bactériologique dans la surveillance des infections bronchiques à Pseudomonas aeruginosa survenant au cours de la mucoviscidose.

BACKGROUND: Sputum bacteriological analysis of cystic fibrosis (CF) patients colonised by Pseudomonas aeruginosa is difficult. The bronchial persistence of these bacteria involves phenotypical modifications and the many antibiotic treatments result in emergence of multiresistant strains. The aim of this study is to evaluate a new fast identification and sensitivity testing method of P. aeruginosa and other pathogenic bacteria in sputum of CF patients. It is based on applying a gradient of antibiotic (E-test strip) onto an agar plate inoculated with the sputum. OBSERVATIONS: 310 sputum, collected from adults and children colonised by P. aeruginosa, were analysed by this new method. This method allowed a direct reading of the minimal concentration of antibiotic that inhibited the totality of Gram-negative strains and the detection of resistant pathogenic bacteria inside the ellipse of inhibition. Results obtained by this new method were compared with the conventional method for identification and antimicrobial sensitivity. CONCLUSION: This new method, studying with CF patient colonised by P. aeruginosa, appears interesting, with a sensibility equal or higher than 89% in detection of the bacteria and their sensitivity to antibiotics. Furthermore it allows a saving of time and simplified results.

Effect of intermittent inhaled tobramycin on sputum cytokine profiles in cystic fibrosis.

OBJECTIVES: The aim of this study was to evaluate the anti-inflammatory properties of intermittent inhaled tobramycin. METHODS: To establish this, we initiated a prospective study to measure the concentration of the three pro-inflammatory cytokines IL-8, IL-6 and TNF-alpha in the sputum from 20 cystic fibrosis (CF) patients (15 teenagers and 5 young adults) during cycles and off cycles. RESULTS: A significant decrease in IL-8 (P = 0.001) and a more moderate decrease in IL-6 (P = 0.046) and TNF-alpha (P = 0.052) levels were observed during cycles, even if no significant decrease in the number of leucocytes was observed. CONCLUSIONS: These results associated with a decrease in the Pseudomonas aeruginosa population can contribute in part to the beneficial effect of intermittent inhaled tobramycin on pulmonary function.

Differential effect of retinoic acid and triiodothyronine on the age-related hypo-expression of neurogranin in rat.

Given the important role of retinoids and thyroid hormone for optimal brain functioning and the tenuous relationship between retinoic acid (RA) and triiodothyronine (T3) signalings, we compared the effects of RA or T3 administrations on RA and T3 nuclear receptors (RAR, RXR and TR) and on their target genes, neuromodulin (GAP43) and neurogranin (RC3) in 24-month-old rats. Quantitative real time PCR and western blot analysis allowed us to verify that retinoid and thyroid signalings and GAP43 and RC3 expression are affected by age. By in situ hybridization we observed a decreased expression of RC3 in hippocampus, striatum and cerebral cortex. RARbeta, RXRbeta/gamma and GAP43 were up-regulated by RA as well as T3 treatment. The abundance of TRalpha/beta mRNA and RC3 expression were only increased by T3 administration in the whole brain. This up-regulator effect of T3 on RC3 was only observed in the striatum. During aging, T3 become a limiting factor alone able to correct the age-related concomitant hypo-activation of retinoid and thyroid signalings and alterations of synaptic plasticity.

Energetic cost of physical activity in cystic fibrosis children during Pseudomonas aeruginosa pulmonary exacerbation.

Chronic pulmonary infection by Pseudomonas aeruginosa is observed in 50% of patients with cystic fibrosis and requires the use of recurrent intravenous therapy. A decrease of resting energy expenditure (REE) and an increase of physical activity (PA) after intravenous anti-P. aeruginosa therapy (IVAT) is observed while total energy expenditure (TEE) does not change. A decrease in the energetic cost of physical activity (ECPA) could be hypothesized but has never been studied. Our aim was to assess the evolution of ECPA after home IVAT in both standardized condition at hospital and in free-living condition twice before and after IVAT. Sixteen CF patients (nine boys, seven girls) chronically colonized by P. aeruginosa with a mean age of 12.1+/-2.3 years (range 7.1-14.6) were studied before and after IVAT. Each patient passed throughout a visit in hospital: weight, height and fat-free mass were measured. Then, energy expenditure (EE) measured by indirect calorimetry and heart rate (HR) were simultaneously recorded at different levels of PA: REE, and at different intensity of physical activities on a cycloergometer using an incremental increase of the power brake force. Physical activity energy expenditure (PAEE) was computed in laboratory condition using PAEE=EE-BEE (basal energy expenditure). Linear regression between PAEE and power brake force was fitted for each patient before and after IVAT. ECPA in standardized conditions was compared at different range of power brake force using area under the curve (AUC). After coming back at home, 24 h TEE using the heart rate monitoring technique and PA by triaxial accelerometry were simultaneously measured in free-living condition for 24 h during a school day. ECPA in free-living conditions was compared by the ratio PAEE:PA where PAEE=DEE-REE (DEE=daily energy expenditure). After IVAT, median AUC between 60 and 90 W in standardized condition decreased significantly by -15.4% (median 14.9, range 8.8-30.3 vs. median 12.6, range 8.5-17.6; P<0.05, Wilcoxon rank test) while the decrease for lower range of power work load did not reach significance. Spearman correlation was significant between variations of forced expiratory volume in 1 s and variation of AUC at 30-60 W before and after IVAT in standardized condition. In free-living conditions, ratio PAEE/PA did not vary significantly (median 3.4, range 1.6-6.4 vs. median 2.8, range 1.4-4.8; NS). Our data demonstrate a decrease of ECPA after IVAT in standardized conditions for moderate level of PA (60-90 W), but not in free-living conditions. The decrease of ECPA was probably due to a decrease in the energetic cost of breathing after IVAT, that is particularly relevant to promote PA in CF patients.

[Hereditary neuralgic amyotrophy: a paediatric and familial presentation of Parsonage-Turner syndrome]. / Névralgie amyotrophiante héréditaire ou forme pédiatrique familiale du syndrome de Parsonage et Turner.

Hereditary neuralgic amyotrophy is a rare disorder, characterized by recurrent attacks of pain in a brachial plexus distribution. We report the case of a 12-year-old boy with several attacks of pain and atrophy of the muscles of the shoulders. The age of onset of this disease is variable, most frequently in the second or third decade. Pediatric onsets, during the first decade are rare. The differences between the hereditary neuralgic amyotrophy and the sporadic Parsonage-Turner syndrome are painful recurrent episodes of weakness and similar familial cases. The analysis of several families has shown that hereditary neuralgic amyotrophy phenotype is heterogeneous and two different clinical courses can be discerned. Recent evidence indicates that HNA is genetically heterogeneous. Pathophysiology of the disease remains unclear, so the treatment is not clearly established.

[Epidemiology of infections associated to "Burkholderia cepacia complex" in the course of cystic fibrosis]. / Epidémiologie des infections provoquées par les bactéries du "complexe Burkholderia cepacia" au course de la mucoviscidose.

Within a few years bacteriological knowledge on Burkholderia cepacia species has progressed considerably. Within bacterial classification (taxonomy), B. cepacia gathers eight species and one species on standby of nomenclature (genomovar VI); the whole of these species constitutes the "B. cepacia complex" or B. cepacia "sensu lato" and the denomination B. cepacia "sensu stricto" is attributed to the genomovar I. These new data call into question the knowledge on the clinic and the epidemiology of B. cepacia "sensu lato" infection in the course of cystic fibrosis. Among these newly described species, B. cenocepacia (formerly genomovar III) and B. multivorans (formerly genomovar II) are the most frequent species and together they represent more than 90% of infections associated to "B. cepacia complex" in the course of cystic fibrosis. B. cenocepacia is often associated to the "cepacia syndrome" which is characterized as a fatal necrotizing pneumonia with bacteremia. The progress of molecular epidemiology allowed the description of bacterial clones of which some are highly transmissible from person-to-person. Their distribution varies according to the species and the geography. The identification of these new species appears particularly difficult and, by the fact, the data on taxonomy and molecular epidemiology can be provided only by highly specialized reference centers.

Expression of neurogranin and neuromodulin is affected in the striatum of vitamin A-deprived rats.

Our previous data showed that vitamin A deficiency (VAD) induces, in whole brain, a reduced amount of mRNA for brain retinoic acid (RA) and triiodothyronine (T3) nuclear receptors (i.e., RAR, RXR, and TR, respectively), which is accompanied by reduced amounts of mRNA and protein of neurogranin (RC3, a neuronal protein involved in synaptic plasticity) as well as selective behavioral impairment. Given the important role of retinoids for optimal brain functioning, the effects of vitamin A depletion and subsequent administration of RA or T3 on the mRNA levels of RA and T3 nuclear receptors and on two target genes' (RC3 and neuromodulin or GAP43) mRNA and protein levels were examined in the hippocampus, striatum, and cerebral cortex. A quantitative real-time polymerase chain reaction (PCR), in situ hybridization, and Western blot analysis demonstrated that the striatal region is the brain site where both RA and T3 signaling pathways are most affected by VAD. Indeed, rats fed a vitamin A-free diet for 10 weeks exhibited decreased expression of RAR, RXR, TR, RC3, and GAP43 in the striatum. The administration of T3 to these vitamin A-deprived rats reversed the reduction in mRNA levels of RA and T3 nuclear receptors and in mRNA and protein levels of target genes in this region. These data suggest that modifications that appear preferentially in the striatum, a region highly sensitive to vitamin A bioavailability, may contribute to neurobiological alterations and the spatial learning impairment that occurs in vitamin A-deprived animals.